diff --git a/src/eval/methods.rs b/src/eval/methods.rs index 19f3d65ee..57fff681b 100644 --- a/src/eval/methods.rs +++ b/src/eval/methods.rs @@ -108,6 +108,13 @@ pub fn call( _ => return missing(), }, + Value::Color(color) => match method { + "lighten" => Value::Color(color.lighten(args.expect("amount")?)), + "darken" => Value::Color(color.darken(args.expect("amount")?)), + "negate" => Value::Color(color.negate()), + _ => return missing(), + }, + _ => return missing(), }; diff --git a/src/geom/paint.rs b/src/geom/paint.rs index 522db1bed..121bb003e 100644 --- a/src/geom/paint.rs +++ b/src/geom/paint.rs @@ -67,6 +67,37 @@ impl Color { Self::Cmyk(cmyk) => cmyk.to_rgba(), } } + + /// Lighten this color by the given factor. + pub fn lighten(self, factor: Ratio) -> Self { + let ratio = factor.get(); + + match self { + Self::Luma(luma) => Self::Luma(luma.lighten(ratio)), + Self::Rgba(rgba) => Self::Rgba(rgba.lighten(ratio)), + Self::Cmyk(cmyk) => Self::Cmyk(cmyk.lighten(ratio)), + } + } + + /// Darken this color by the given factor. + pub fn darken(self, factor: Ratio) -> Self { + let ratio = factor.get(); + + match self { + Self::Luma(luma) => Self::Luma(luma.darken(ratio)), + Self::Rgba(rgba) => Self::Rgba(rgba.darken(ratio)), + Self::Cmyk(cmyk) => Self::Cmyk(cmyk.darken(ratio)), + } + } + + /// Negate this color. + pub fn negate(self) -> Self { + match self { + Self::Luma(luma) => Self::Luma(luma.negate()), + Self::Rgba(rgba) => Self::Rgba(rgba.negate()), + Self::Cmyk(cmyk) => Self::Cmyk(cmyk.negate()), + } + } } impl Debug for Color { @@ -91,7 +122,7 @@ impl LumaColor { /// Convert to an opque RGBA color. pub const fn to_rgba(self) -> RgbaColor { - RgbaColor::new(self.0, self.0, self.0, 255) + RgbaColor::new(self.0, self.0, self.0, u8::MAX) } /// Convert to CMYK as a fraction of true black. @@ -103,6 +134,21 @@ impl LumaColor { (self.0 as f64 * 0.90) as u8, ) } + + /// Lighten this color by a factor. + pub fn lighten(self, factor: f64) -> Self { + Self(self.0.saturating_add(((u8::MAX - self.0) as f64 * factor) as u8)) + } + + /// Darken this color by a factor. + pub fn darken(self, factor: f64) -> Self { + Self(self.0.saturating_sub((self.0 as f64 * factor) as u8)) + } + + /// Negate this color. + pub fn negate(self) -> Self { + Self(u8::MAX - self.0) + } } impl Debug for LumaColor { @@ -135,6 +181,46 @@ impl RgbaColor { pub const fn new(r: u8, g: u8, b: u8, a: u8) -> Self { Self { r, g, b, a } } + + // Lighten this color by a factor. + // + // The alpha channel is not affected. + pub fn lighten(self, factor: f64) -> Self { + let lighten = |c: u8| c.saturating_add(((u8::MAX - c) as f64 * factor) as u8); + + Self { + r: lighten(self.r), + g: lighten(self.g), + b: lighten(self.b), + a: self.a, + } + } + + // Darken this color by a factor. + // + // The alpha channel is not affected. + pub fn darken(self, factor: f64) -> Self { + let darken = |c: u8| c.saturating_sub((c as f64 * factor) as u8); + + Self { + r: darken(self.r), + g: darken(self.g), + b: darken(self.b), + a: self.a, + } + } + + // Negate this color. + // + // The alpha channel is not affected. + pub fn negate(self) -> Self { + Self { + r: u8::MAX - self.r, + g: u8::MAX - self.g, + b: u8::MAX - self.b, + a: self.a, + } + } } impl FromStr for RgbaColor { @@ -161,7 +247,7 @@ impl FromStr for RgbaColor { return Err("string has wrong length"); } - let mut values: [u8; 4] = [255; 4]; + let mut values: [u8; 4] = [u8::MAX; 4]; for elem in if alpha { 0 .. 4 } else { 0 .. 3 } { let item_len = if long { 2 } else { 1 }; @@ -250,6 +336,42 @@ impl CmykColor { a: 255, } } + + /// Lighten this color by a factor. + pub fn lighten(self, factor: f64) -> Self { + let lighten = |c: u8| c.saturating_sub((c as f64 * factor) as u8); + + Self { + c: lighten(self.c), + m: lighten(self.m), + y: lighten(self.y), + k: lighten(self.k), + } + } + + /// Darken this color by a factor. + pub fn darken(self, factor: f64) -> Self { + let darken = |c: u8| c.saturating_add(((u8::MAX - c) as f64 * factor) as u8); + + Self { + c: darken(self.c), + m: darken(self.m), + y: darken(self.y), + k: darken(self.k), + } + } + + /// Negate this color. + /// + /// Does not affect the key component. + pub fn negate(self) -> Self { + Self { + c: u8::MAX - self.c, + m: u8::MAX - self.m, + y: u8::MAX - self.y, + k: self.k, + } + } } impl Debug for CmykColor { diff --git a/tests/ref/utility/color.png b/tests/ref/utility/color.png index a03795f7f..496013bb7 100644 Binary files a/tests/ref/utility/color.png and b/tests/ref/utility/color.png differ diff --git a/tests/typ/utility/color.typ b/tests/typ/utility/color.typ index 449655bf2..3ff141d4a 100644 --- a/tests/typ/utility/color.typ +++ b/tests/typ/utility/color.typ @@ -8,17 +8,38 @@ // Alpha channel. #test(rgb(255, 0, 0, 50%), rgb("ff000080")) +// Test color modification methods. +#test(rgb(25, 35, 45).lighten(10%), rgb(48, 57, 66)) +#test(rgb(40, 30, 20).darken(10%), rgb(36, 27, 18)) +#test(rgb("#133337").negate(), rgb(236, 204, 200)) +#test(white.lighten(100%), white) + --- // Test gray color conversion. // Ref: true #rect(fill: luma(0)) #rect(fill: luma(80%)) +--- +// Test gray color modification. +#test(luma(20%).lighten(50%), luma(60%)) +#test(luma(80%).darken(20%), luma(64.5%)) +#test(luma(80%).negate(), luma(20%)) + --- // Test CMYK color conversion. // Ref: true -#rect(fill: cmyk(69%, 11%, 69%, 41%)) -#rect(fill: cmyk(50%, 64%, 16%, 17%)) +#let c = cmyk(50%, 64%, 16%, 17%) +#rect(width: 1cm, fill: cmyk(69%, 11%, 69%, 41%)) +#rect(width: 1cm, fill: c) +#rect(width: 1cm, fill: c.negate()) + +#for x in range(0, 11) { + square(width: 9pt, fill: c.lighten(x * 10%)) +} +#for x in range(0, 11) { + square(width: 9pt, fill: c.darken(x * 10%)) +} --- // Error for values that are out of range.